In this project, let’s learn how to make an Inverter – a Simple 40 watts inverter circuit using minimal components. An inverter circuit is often used in DC to AC applications and is a necessary in many electronics applications. The heart of this circuit is digital IC CD4047 – which is a very popular component.

Let’s Build our Simple 40 Watt Inverter

This is the schematic of a simple 40W , 12 volts to 220 Volts inverter.You don’t believe, this is simple and cheap and working for me for last 4 years.The heart of the circuit is a CD 4047 IC which is wired as an astable multi vibrator here.Resistance and Capacitance at pin 1&2 determines the out put frequency.Here it is set to 60Hz.Due to this a two 180 degree out of phase ,120 Hz , 50% duty cycle waveforms will appear at pin 10 & 11.These waves are amplified by the complementary symmetry amplifier made of transistors BC 337 & TIP 3055 to drive the out put transformer.Don’t get feared of the technical terms, just wire it on a all purpose PCB.It is simple and will work.Don’t worry about the transformer windings ,buy a 220-110-0 primary,12-0-12 secondary , <50W transformer.You can select output voltage of 110V or 220V by a two way switch using such a transformer.Don’t worry if you don’t have such a transformer, a simple 220 to 12-0-12 will also do the trick sacrificing the 110V option or vice versa.The best way to get a transformer is to break all useless electronic devices in your trash.Most probably you will find the transformer or more components needed here!

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Simple Inverter Circuit Diagram:

Tips :

First wire to oscillator part only.Then check out put Pin 10 &11 of CD4047 to obtain the required wave forms ( two 120Hz ,180 degree out of phase,50% duty cycle waves.

Then connect transistors ,transformer and load (25 W bulb for test).See it working!.

Hallo , your blueprint is good! I have a power supply at 50 Hz and by the use of this inverting circuit i want to produce an 120 volt at 60Hz. I connected the Capacitor and the resistors between legs 1,2,3 as shown. Firstly i should not care for the capacitors polarity on pins 1,3 ? Secondly i can not adjust the frequency of the produced signal . I always get 50 Hz. How can i change this? Is only the resistors and capacitor involved on produced signals frequency? Thank you in advance.

hello sir i have a problem during designing this circuit that ic you have used is not in the softwares can you tell another equivalent ic number which can perform the same task
reply as soon as poosible
thankng u

Normally they are 250 VA type, using a 12 volts 7 AH battery of C20 rating. That is you can draw 350mA for 20 Hours. That is 4.2 watts for 20 hours. That does not mean that you can draw 42 watts for 2 hours and 336 watts for 15 minutes. As you draw higher current the battery rating will come down drastically. If you draw around 200 watts it will work for 15 minutes with a fully charged fresh battery. 15 minutes is more than sufficient to save the work and shut down the computer. For longer duration operation you have use external higher AH rated battery provided the electronics in the UPS can take care of the longer duration of operation at higher VA rating. You have to us external charger for the battery as the UPS can take care of only 7 AH battery.

Hi CD4047 is the oscillator with two 180 deg phase difference output this is fed to a push pull power driver transistor pair BC337 & 2N3055. which in turn drives the primary 12 volt winding of the inverter transformer, which is a step up transformer its output is available as 100 volt or 220 volt at 60Hz square wave.

Are you sure it’s a sine wave output? Doubt it, 4047 IC outputs pulse square wave.. do you have any proof or tried already this circuit output on an oscilloscope? I think it’s just a square wave not even a modified sine wave.

Sir I don’t have oscilloscope or frequency meter etc to make sure Im having two 120Hz out of phase waves
All this circuit told by you is perfect right? So may i just make it like the way you have drawn without any modifications or assurance to check the output wave?

Just a little heads up… This circuit is good, but may cause some confusion.

The ZENER DIODE that is rated 10 VOLTS and .5 VOLTS is actually a 10 VOLT 5 WATT Zener Diode.

All RESISTORS should be 1/2 Watt 5-10% Tolerance.

All CAPACITORS should be Ceramic and 20+ Volts.

All TRANSISTORS should have HEATSINKS!

The Amp rating of the BATTERY, FUSE, and TRANSFORMER must match up! (A regulator can be used to regulate the battery power).

By following the schematics and these instructions, you should be able to build a good Inverter. Remember, 120 Volts is a lot, and at 40 Watts is well beyond lethal. Electrolytic Capacitors will be OK, but Ceramics are recommended as they have a longer lifespan.

Hallo, this be very good circuit, can you please tell me, I have many many wall wart transformers and my old power supply transformers, but not one center tap in thee whole mess. Short of stripping a core and re-winding, I read somewhere way back when, that two Identical transformers can be joined in such a way as to produce a centerTap, but that the polarity “-, +” on each trans should be Identified, and then hooked up,,,WHICH way? I cannot remember? Thanks so muchous for this circue,

Donot use a 9-0-9 transformer,the output voltage will be very high.use 12-0-12.You can believe me because i made this.it is working in good condition.use a medium sized heat sink for transistor.I lost one transistor because its sink was loose.its very cheap except for the 5A transformer.

IRF250 or its equivallent can be used directly in this same circuit. Standard 10-0-10volt inverter transformers can be used. If freewheeling diodes are not built-in in the IRF use IN5404 parellel in reverse biased with IRF.

thats nice
but i want the output voltage to be 12 v
i think removal of transformer would do that ? ?
what do u say ?
how much amperes would it give in case of 12 v ?
i want to use it with a 12v dry battery for my network router + switch

HI please help me i have made the circuit for the model making competition but the problems is simple IT isnt working when i connect the circuit it draws 1.1A please sombody help meeee thanks in advance

Hello,
Thanks for the simple and easy inverter design, please can u help me to upgrade the circuit to 2000 watts ? , i know that more transistors and a bigger transformer should be added and that the power source should be no less than 48 volts DC , but i don’t know how to put everything together.